Hi gang. I am at the part of the build that, for some reason, is by FAR the hardest for me. That is doing the impenetrable area on the bottom of the hull to 1" below the water line. I have tried a couple of methods, and neither seems to work staisfactorily. I would LOVE to use the skin with thin plywood method, but I just can't get the wood to play nice. Even on areas of the hull where there is not much of a curve, the wood does not want to bend with the shape of the ribs. I glue the wood piece to the keel, glue it down to the widest rib, and start to wrap it around the hull. However, by the time it reaches where it needs to stop, I have to use a LOT of pressure to keep it bent to the proper shape. When I glue it down to two adjoining ribs, the resistance to bending is so great that the plywood peice curves outward between the ribs. Am I missing some kind of super secret technique here? The wood is 1/64 and I have tried to wet it down as well. What am I doing wrong? Please help!
I had the exact same problem, I could not for the life of me get it to work. I solved this problem by doing away with this method and instead using the balsa blocks in between the ribs and then sanded to shape as shown on the second page of the Bearn build thread: http://www.rcnavalcombat.com/Forum/tabid/58/aff/566/aft/407920/afv/topic/Default.aspx
I am with Jstod, I used the thin ply over the ribs method for years. I am fully converted to balsa block between the ribs now. It looks better and it's less painful to get to shape
I built up my H-39 (and BB-44) frame from 1/4" baseboard and ribs. Capped it and made sure it was square during the assembly process. I then bolted it to my work surface. with it flat on the table, I constructed a gantry of sorts, that would hold a pencil at the correct 1" below waterline level. I then slid this rig alongside the hull full length both sides. This left me with an absolute hard area boundary marker. This won't work well with sloppy hulls, since it references absolute to the bottom of the hull. If ribs are too tall or short, it'll crate a technical error. As for material, I use basswood strips for the impenetrable area "armor belt". I use 1/2" width strips for the initial line. To get them into the bends, I soak the puppies in a water /ammonia mix until I can bend them the way I like. I apply the CA glue to the ribs, press the wet strips to it, and the glue cures PDQ. It's easy to screw up, but when done right, it glues and holds, and the flexible wood doesn't try to torque the frame as rigid strips do. Oh, this method works best with the hull secured to the table, but upside down. PRACTICE with a test ribs structure to be sure you get the "wetness" correct. Sometimes, the glue will bubble up and actually secure the plank away from the rib a bit. This method can be done in sections. If the wood is at the sweet spot between rigid and pliable, it will curve beautifully between the ribs and create that nice line we all strive for. No shape alteration of this initial belt should be required. When the first strip line is in place, I add another below it. I keep going till its done. The whole thing gets filled and sealed, and sanded until correct (accurate ribs prevent waste sanding away the planks.) The outside is finished with heavy skin fabric and sealed again. The inner hull gets a few paintings with resin. Ribs at the stern are drained with holes drilled through near the hull skin, and resign is poured in and allowed to settle with the hull at an up angle to create a smooth floor slope for water to quickly run down to the hull bottom. I've never had anything break a basswood armor belt. If I need to replace a section, it's fairly easy. With a CA glue cap-n-seal on the wood, shaving away balsa skin material for repairs is easy, with an X-acto knife sliding along the top edge of the belt.Cleans the wood off down to the glue, and I can sand that down further if the damage requires a more precise fitting.
Quick update: I built the hard area using the balsa block method and it seemed to work rather well. I made the mistake of installing the stuffing tubes first, however, so I will just mark them and leave an open space for them next time. The hull is glassed and I am moving on to the fitting out stage of the build. Thanks gang! Capt. OCD
